The present invention relates to hinges, and, more particularly, to hinges provided with bushings to eliminate metal-to-metal contact between the hinge leaves and to methods for assembling such hinges.
The cooperating leaves of lower cost hinges such as strap and T-hinges are generally formed by metal stamping equipment from heavy gauge steel sheet. These leaves have an attachment portion for securing the hinge to the door or gate and to the associated door or gate frame, and one or more prongs or knuckles thereon which have aligned apertures therethrough and which define a barrel in which is seated a hinge pin or pins.
Metal-to-metal contact between adjacent knuckles during pivoting will produce wear of the parts, especially when the hinge is used to suspend a heavy door or the like. Moreover, the rotation of the pin within the knuckles will also produce wear which is accelerated by dirt and corrosion.
In U.S. Pat. Nos. 3,725,973 and 3,921,225,the hinges have plastic bearings between the knuckles to retard the wear. Other hinges use ball bearings; still others use bushings with axially extending portions and thrust washers. The forming and/or assembly operations required for most of these hinges increase the cost substantially.
It is an object of the present invention to provide a novel and economical hinge which can be readily fabricated and which exhibits relatively long life.
It is also an object to provide such a hinge having a pair of bushings which may be readily assembled to the knuckle of a single knuckle hinge leaf to provide bearing surfaces for the hinge pin and between it and the knuckles of a cooperating two knuckle hinge leaf.
Still another object is to provide relatively simple and low cost methods for making such hinges.